1. Technical Field
The present invention relates to a display apparatus having an edge light type backlight.
2. Description of Related Art
A liquid crystal display apparatus has characteristics such as thin, and low power consumption, recently, due to an improvement of display quality thereof, has been widely distributed as a display alternative to a conventional CRT, and is widely used as an image display apparatus of a television receiving apparatus (hereinafter, referred to as a TV receiving apparatus). Unlike a self-luminous device, the liquid crystal display apparatus needs a backlight as a light source, and displays an image by controlling light transmittance which is determined by electro-optical characteristics of liquid crystals.
The backlight has types of an edge light type (side light type, or light guide plate type), and a direct type.
As a liquid crystal display apparatus having the edge light type backlight, in order to achieve thinning, weight lightening, and narrowing of a frame, there may be a display apparatus in which a backlight unit formed by housing a light guide plate, optical sheets, and a light emitting diode (LED) substrate in a rectangular box-shaped chassis is disposed at a back surface of a liquid crystal display panel (hereinafter, referred to as a display panel) to form a display module, and the display module is covered with a frame. The LED substrate includes a plurality of LEDs mounted on a flat surface of an elongated substrate. When the backlight unit is an edge light type from one side, the LED substrate is disposed to face, for example, one long side surface of a rectangular plate-shaped light guide plate. Light which is emitted from the LEDs and has entered from the long side surface of the light guide plate is emitted from a main surface of the light guide plate, and the back surface of the liquid crystal panel is irradiated with the light.
There are cases that the LED substrate is mounted on a side plate facing the long side surface of the light guide plate of the chassis; and the LED substrate is mounted on a short side portion of an LED holding plate formed in an L shape in a side view, while the chassis does not have the side plate. In the latter case, the long side portion of the LED holding plate is connected to the chassis.
The display panel is configured so as to be held by a holding member formed in a rectangular plate shape, and the holding member covers the LED substrate, as well as the LED holding plate.
In addition, a peripheral edge part of the display panel and the holding member are covered with a bezel formed in a rectangular plate shape.
In order to fix the holding member and the bezel to a portion which holds the LED substrate of the backlight unit such as the LED holding plate, screws are used.
There are restrictions on a design of the above-described thinning and narrowing of a frame, and recently, to realize high resolution and high definition such as 4K2K, a source substrate, or the like which is disposed on an outer surface of the holding member is increased in a size (increased in an area). Thereby, there is a problem that, when the LED substrate is disposed on an inner surface inside of the outer surface of the holding member, it is not possible to sufficiently secure a space for fixing the screws.
As a liquid crystal display apparatus which has achieved narrowing of the frame, there is an invention disclosed in Japanese Patent Laid-Open Publication No. 2001-356321.
FIG. 13 is a partial cross-sectional view illustrating a liquid crystal display apparatus of Japanese Patent Laid-Open Publication No. 2001-356321.
The liquid crystal display apparatus includes a display panel 21, a holding member 26, a bezel 27, and a mounting member 39. The holding member 26 has a side part, and holds the display panel 21. The bezel 27 has a front plate 272 which covers a peripheral edge part of the display panel 21, and a side plate 271 which extends substantially parallel to the side part of the holding member 26, and has a screw insertion hole 275. The mounting member 39 is formed in substantially a U shape, is detachably mounted on the side part of the holding member 26, and has a female screw 391 to which a screw 40 inserted into the screw insertion hole 275 of the bezel 27 is screwed.
The display apparatus includes the mounting member 39 as described above, and a frame region is reduced by as much as an amount disposing the mounting member 39, such that there are problems of not being able to narrow the frame, as well as an increase in manufacturing costs.
In addition, the mounting member 39 formed in substantially a U shape is configured to be screwed to the side part of the holding member 26, and it is conceivable that, when fastening the screw 40 to the female screw 391, a positional shift may occur therebetween, and fixation of the mounting member 39 to the holding member 26 may be weakened.
Further, the mounting structure has a problem that it is not possible to cope with a demand for disposing a plurality of source substrates while decreasing an interval between the outer surface of the holding member 26.
FIG. 14 is a partial cross-sectional view illustrating another conventional display module.
The display module includes a display panel 21, an optical sheet group 22 including, for example, three optical sheets, a light guide plate 23, a holding plate 24, a holding member 26, a bezel 27, an LED substrate 30, a reflection sheet 38, and a mounting member 41.
The LED substrate 30 including a plurality of LEDs 31 mounted thereon is supported by the holding plate 24, with being disposed to face a long side surface of the light guide plate 23.
The holding plate 24 is made of, for example, aluminum, and includes a lower plate part 241 which covers a lower long side surface of the light guide plate 23, and a back plate part 242 which is provided perpendicular to the lower plate part 241 and extends in a longitudinal direction of the light guide plate 23.
The reflection sheet 38 is a white sheet, and is made of, for example, a resin material having an optical reflectivity such as polyethylene terephthalate (PET), polycarbonate (PC) or the like. The reflection sheet 38 is provided at the back plate part 242 through a spacer 29. The reflection sheet 38 is provided on the outer surface of the light guide plate 23.
The optical sheet group 22 is a sheet group including a diffusion sheet, lens sheet, reflection type polarizing sheet, and the like, and is disposed at a front of the main surface of the light guide plate 23.
The holding member 26 has a lower plate part 261, a panel abutting part 262, and a sheet abutting part 263.
The lower plate part 261 extends in a horizontal direction, and abuts the lower plate part 241 of the holding plate 24 to support the lower plate part 241. The lower plate part 261 has four source substrates (not illustrated) disposed beside a lower surface thereof. A screw insertion hole 268 is provided in a gap portion of the lower plate part 241, in which an adjacent source substrate is disposed.
The panel abutting part 262 is erected on the lower plate part 261, and abuts against a lower end edge part of a back surface of the display panel 21 through a buffer member 33.
The sheet abutting part 263 extends from an upper side of the panel abutting part 262, and a back surface of the sheet abutting part 263 abuts on a lower portion of a front surface of the optical sheet group 22 through a buffer member 34.
The bezel 27 is a frame body formed in an L shape in the side view, and has a side plate 271, and a front plate 272. The side plate 271 extends in the horizontal direction, and covers the source substrate and the lower plate part 261 of the holding member 26. The front plate 272 is provided perpendicular to the side plate 271, and the back surface thereof abuts a lower end edge part of the front surface of the display panel 21 through a buffer member 28. The front plate 272 is provided with a plurality of screw insertion holes 278 in the lower portion thereof.
The mounting member 41 is provided with a plurality of female screws 411 in the lower portion thereof. The mounting member 41 is mounted on the back surface of the back plate part 242 of the holding plate 24.
In addition, the bezel 27 and the holding member 26 are configured so as to be mounted to the holding plate 24, by inserting a screw 42 into the screw insertion holes 278 and 268 to be screwed to the female screws 411.
The display module has problems that, since the mounting member 41 is provided, a thickness of the display module is thickened and the manufacturing costs are increased, as well as, since the screw insertion structure is provided in the gap between the lower plate part 261 of the holding member 26, in which the source substrate is disposed, it is not possible to cope with a demand for decreasing the gap.
As a fixing structure of another bezel 27 and the holding member 26 to the holding plate 24, there is a structure in which a stud is caulked to the lower plate part 241 of the holding plate 24, a female screw is formed in the stud, a screw penetrates the side plate 271 from an outside of the side plate 271 of the bezel 27, and in this state, the screw is screwed to the female screw.
In this case, there are problems that, since the stud is provided in the lower plate part 241, manufacturing processes become complicated, and since the screw insertion structure is provided in the gap between the lower plate part 261, in which the source substrate is disposed, it is not possible to cope with a demand for decreasing the gap.
Further, as a fixing structure of the bezel 27 and the holding member 26 to the backlight unit, a structure, in which a female screw is provided in a gap between LEDs 31 of the LED substrate 30, a screw penetrates the side plate 271 from the outside of the side plate 271 of the bezel 27, and in this state, the screw is screwed to the female screw, may be conceived.
In this case, there are problems that, engagement of the screw to the female screw is decreased, and the screw abuts on the LED substrate 30, such that the LED substrate 30 may be damaged.